Ringworm can spread easily from one person to another. You can catch ringworm if you touch someone who has the infection, or if you come into contact with items contaminated by the fungus, such as combs, unwashed clothing, and shower or pool surfaces. You can also catch ringworm from pets that carry the fungus. Cats are common carriers.

The fungus that causes ringworm thrive in warm, moist areas. Ringworm is more likely when you are often wet (such as from sweating) and from minor injuries to your skin, scalp, or nails.

Symptoms

Symptoms of ringworm include:

Itchy, red, raised, scaly patches that may blister and ooze.

The patches tend to have sharply-defined edges.

Red patches are often redder around the outside with normal skin tone in the center. This may look like a ring.

If ringworm affects your hair, you will have bald patches.

If ringworm affects your nails, they will become discolored, thick, and even crumble.

Signs and tests

Most of the time, your health care provider can diagnose ringworm by looking at your skin. The fungus may glow when your skin is examined with a blue light (called a Wood's lamp) in a dark room.

Treatment

Apply over-the-counter antifungal or drying powders, lotions, or creams that contain miconazole, clotrimazole, or similar ingredients.

Don't wear clothing that rubs against and irritates the area.

Wash sheets and nightclothes every day while you are infected.

Your health care provider may prescribe pills to treat the fungus if you have:

A severe case of ringworm

Ringworm that keeps coming back or that lasts for a long time

Ringworm in your hair

You may need medicines such as ketoconazole, which are stronger than over-the-counter products. You may also need antibiotics to treat skin infections from strep or staph that are caused by scratching the area.

Infected pets also should be treated.

Expectations (prognosis)

Skin medicine usually treats ringworm within 4 weeks. If your ringworm infection is severe or it does not respond well to self-care, it will usually respond quickly to antifungal pills.

Complications

Call your doctor right away if you have any signs of a bacterial infection, which can result from scratching. These signs include swelling, warm skin, sudden worsening in redness of the patches, red streaking, pus, drainage, and fever.

Call your doctor if:

You have ringworm on your scalp or beard

Your skin does not improve after 4 weeks of self-care

The rash spreads and you have diabetes or a weakened immune system due to disease or certain medications

Prevention

To prevent ringworm:

Keep your skin and feet clean and dry.

Shampoo regularly, especially after haircuts.

Do not share clothing, towels, hairbrushes, combs, headgear, or other personal care items. Such items should be thoroughly cleaned and dried after use.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only - they do not constitute endorsements of those other sites. Copyright 2009 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.